Fuel injection nozzle



May 3, 1966 M. J. BERLYN 26,016

FUL M INJECTION NOZZLE Original Filed Feb. 4, 1963 INVENTOK MAETlN J.BETELYN 7:7 1. 011g ATTOPNE)! Reissued May 3, 1966 26,016 FUEL INJECTIONNOZZLE Martin J. Berlyn, Beacon Lodge, Texas St., Morley, Leeds, EnglandOriginal No. 3,118,611, dated Jan. 21, 1964, Ser. No.

256,052, Feb. 4, 1963. Application for reissue Feb. 8,

1965, Ser. No. 448,904

13 Claims. (Cl. 239-533) Matter enclosed in heavy brackets appears inthe original patent but forms no part of this reissue specification;matter printed in italics indicates the additions made by reissue.

This invention relates to fuel injection nozzles for internal combustionengines and more particularly, to nozzlcs for diesel engines of theopen-chamber direct-injection type.

In such engines, the use of spring-loaded differentialvalvemultiple-orifice nozzles is now almost universal. No other type ofnozzle has provided such generally satisfactory solutions to theproblems of formation, dispersion, and penetration of fuel spray in openchamber combustion spaces.

Contemporary nozzles for open-chamber diesel engines are excessivelycostly, but their major disadvantage is that they are objectionablybulky. It is to be understood that these shortcomings apply to thecomplete assembly of nozzle and nozzleholder as a unit, not necessarilyto the nozzle tip itself.

The designer of a diesel cylinder head must make best possible use ofavailable space, but there is mutual conflict between space requirementsof head structure, valves and porting for air and exhaust, adequate flowpaths for cooling tluid, and studding for securing the head to theblock.

Structural properties of materials and the natural laws of fluid flowand heat exchange govern all aspects of head design once the space forthe injection nozzle assembly has been allocated.

Since the nozzle assembly must be located in or near the centre of thehead, its size and shape prescribe the space available (between itselfand the boundaries of the head) for all the other things included in thecomplete head design.

Compared with the very small nozzle tip, incorporating the fuel sprayorifices, the nozzle-and-holder assembly is usually so large as to be aserious impediment to good cylinder head design.

Explanation of the relatively great size of the conventional nozzleassembly is to be found in the arrangement of the nozzle valve. Thedifferential valve is always inwardly opening. This is to say that itopens towards the incoming fuel. Since fuel under pressure from aninjection pump flows through the nozzle towards the cylinder of theengine it follows that, with an inwardly opening nozzle valve, gaspressure from the engine cylinder acting through the nozzle orificestends to hold the nozzle valve open, following injection, when it oughtto close. The nozzle valve spring must therefore be capable of exertingthe considerable force necessary to close the valve against cylinderpressure, and the appropriate spring is necessarily quite large.

Another shortcoming of many contemporary nozzle assemblies is that thebody of the nozzle holder is axially compressed by the bolting employedfor making a gastight seal between the holder and its seat in thecylinder head. The slight decrease in length of the holder body due tocompressive deformation can disturb the nozzle valve spring setting. Inorder to restrict such maladjustment to the minimum, such nozzle holderbodies are made with a very substantial cross-section throughout thatportion subjected to compression by the bolting load.

A further disadvantage of the conventional nozzle assembly is that itrequires a leak-off tube to carry away fuel which has leaked to theatmospheric side of the lapped fit of the differential valve. Theleak-off tubing of a multicylinder diesel engine is both expensive andirritating; it impairs accessibility and appearance. Because an enginewill run without leak-off tubing, operators sometimes omit to replace itfollowing a nozzle inspection so that in subsequent operation of theengine, small amounts of fuel may ooze down the side of the engine whichthen readily accumulates air-borne dirt; or the leak-off oil mayaccumulate in the bilges of a vessel where it is a fire hazzard; or itmay find its way to the lubricating oil sump of the engine where itprogressively dilutes the lubricating oil, with potentially calamitousresults.

The injection nozzle assembly according to this invention ischaracterized by inherent compactness, by immunity from maladjustmentdue to deformation. and by elimination of leak-oil and the concomitantplumbing.

An object of this invention is to provide a fuel injec tion nozzleassembly for diesel engines which is inherently and significantly morecompact than contemporary nozzle assemblies for equivalent applications.

Another object is to provide a fuel injection nozzle assembly from whichthere is no fuel leak-ofi and which, consequently, requires no leak-01fplumbing.

Another object is to provide a simple fuel injection nozzle assemblyrequiring no lapped [its and of relatively low manufacturing cost.

Another object is to provide a fuel injection nozzle assembly of unitaryconstruction and of such low cost that it may be discarded and replacedat less than the cost of reconditioning a conventional nozzle assembly.

Referring to the drawings:

FIG. 1 is a fragmentary partial section of the assembly in the plane ofthe axis;

FIG. 2 is a transverse section as at 22 of FIG. 1: and

FIG. 3 is an elevation of a typical execution of the whole assembly to asmaller scale.

With particular reference to FIG. I, the assembly comprises four parts,nozzle holder 10, valve 11, spring 12 and nozzle 13.

Holder 10 is provided with central duct 14 for incoming fuel, valve seat15, counterbore 16. spring chamber 17, nozzle seat 18 and deformableskirt 19 of reduced wall thickness. Holder 10 is also provided withgasket seat 20, installing thread 21, hexagon head 22 and union thread23.

Valve 11 is provided with boss 24 having a tapered face 25 whichcooperates with valve seat 15 to effect blocking of duct 14. The lowerend of valve 11 is provided with spring seat 26 and retraction piston27. Between spring seat 26 and retraction piston 27 is a neck 28 whichis provided with radial ducts 29 intersecting axial duct 30.

Between retraction piston 27 and boss 24 is a squared section 31.

Nozzle 13 is provided with spring seat 32, valve lift stop 33 and sachole 34 which is intersected by nozzle orifices 35. The diameter ofspring seat 32 is larger than the inside diameter of spring chamber 17and abuts nozzle seat 18. Nozzle 13 is provided with a curved face 36behind spring seat 31 and, after assembly of valve 11, spring 12 andnozzle 13 into holder 10, deformable skirt 19 is swaged or spun overcurved face 36 of nozzle 13 to lock the assembly permanently together.

In nozzles for open-chamber direct-injection diesel engines of the highspeed automotive type, to which this invcntion is specially applicable,the nozzle opening pressure is usually above 2,000 p.s.i., preferablybetween 2,500 p.s.i. and 3,500 p.s.i. With a differential nozzle valveof conventional type and proportions, the closing pressure is usuallyabout 70% of the opening pressure. Peak injection pressure is generallybetween 6,000 p.s.ig. and 8,500 p.s.i. Maximum gas pressure in thecylinder may be close to the nozzle closing pressure; if these twopressures are too close, malfunctioning results.

Valve 11 is of the so-called "outwardly opening type; this is to saythat it opens towards the engine cylinder and closes towards the fuelinjection pump. Spring 12 urges valve 11 on to seat 15 (towards thepump). Gas pressure from the engine cylinder acts, by way of orifices35, on valve 11 in the same direction as spring 12.

An important feature of outwardly opening nozzle valve 11 is that it isof the differential type and that it is so arranged that, when closed,the relatively large area of retraction piston 27, is subject tocylinder gas pressure in the closing direction while the relativelysmall area of boss 24 is exposed to fuel pressure in the openingdirection.

In an engine functioning normally, of the total force holding valve 11on seat 15 just before the beginning of injection, about 75% is due togas pressure from the cylinder acting on retraction piston 27 and about25% due to spring 12 acting on spring seat 26.

As soon as fuel pressure has lifted valve 11 from seat 15 the openingforce on valve 11 increases greatly by the action of fuel pressure onthe whole area defined by the diameter of retraction piston 27.

When retraction piston 27 emerges from counterbore 16, valve 11 tends tobe in hydraulic balance, but the radial clearance between the peripheryof retraction piston 27 and the inner wall of spring chamber 17 is smallenough to provide mild throttling of the fuel flow; a pressure drop inthe order of 200 p.s.i. across retraction piston 27 is all that isnecessary to carry valve 11 into abutting contact with valve lift stop33; therefore, the fuel pump may have to produce a pressure of 6,750p.s.i. in order to provide an injection pressure" of 6,500 p.s.i.

When the injection pump ends its pumping cycle and the pressure in duct14 drops, the pressure in the engine cylinder is in the order of 1,000p.s.i.; this pressure, acting on retraction piston 27 (and assisted byspring 12) provides a large closing force on valve 11.

As soon as retraction piston 27 enters counterbore 16, the effectivevolume of spring chamber 17 begins to increase, thus fuel is Withdrawnfrom orifices 35 and no dribble takes place after injection.

From the foregoing, it will be seen that I have provided new andimproved means for obtaining all of the objects and advantages of theinvention.

I claim:

1. In a fuel injection nozzle assembly for internal combustion engines[device of the character described], a nozzle body having a duct forincoming fuel, a valve seat at the downstream extremity of said duct, acounterbore downstream of said valve seat, a spring chamber downstreamof said counterbore, a nozzle seat downstream of said spring chamber anda deformable skirt downstream of said nozzle seat, a valve adapted toreciprocate in said counterbore, said valve having a face adapted toengage said valve seat in fluid sealing contact, said valve beingprovided with a piston downstream of said face, said piston being areciprocable fluid sealing fit in said counterbore when said face is incontact with said valve seat, said piston being subject to cylinder gaspressure in the closing direction when the injection pressure drops insaid fuel duct, said valve being provided with a spring seat downstreamof said piston, said nozzle having a valve lift stop and having aperforated tip at its downstream extremity and a flange, and a springengaging said spring seat of said valve and said flange of said nozzle,whereby said spring will assist cylinder gas pressure in urging saidvalve face toward said valve seat, and whereby the eflcctivc volume ofsaid spring chamber is increased and fuel is withdrawn which tends toeliminate fuel dribble after injection and said nozzle engaging saiddeformable skirt whereby the assembly is retained in permanent assembledrelation by deformation of said deformable skirt with the connection ofsaid deformable skirt and said nozzle being the sole fastening forholding the assembly pcrnmnently together.

2. In a fuel injection nozzle assembly for internal combustion engines[device of the character described], a nozzle body having an axial ductfor incoming fuel, a coaxial valve scat at the downstream extremity ofsaid duct, a coaxial counterbore downstream of said valve seat, acoaxial spring chamber downstream of said counterbore, a coaxial nozzleseat downstream of said spring chamber and a coaxial deformable skirtdownstream of said nozzle seat, a valve adapted to reciprocate in saidcounterbore, said valve having a face adapted to engage said valve seatin fluid scaling contact, said valve being provided with a pistondownstream of said face, said piston being a reciprocable flud sealingfit in said counterbore when said face is in contact with said valveseat, said piston being subject to cylinder gas pressure in the closingdirection when the injection pressure drops in said fuel duct, saidvalve being provided with a spring seat downstream of said piston, saidnozzle having a valve lift stop and having a perforated tip at itsdownstream extremity and a flange, and a spring engaging said springseat of said valve and said flange of said nozzle, whereby said springwill assist cylinder gas pressure in urging said valve fucc toward saidvalve seat, and whereby the cficctivc volume of said spring chamber isincreased and fuel is withdrawn which tends to eliminate fuel dribbleafter injection and said nozzle engaging said deformable skirt wherebythe assembly is retained in permanent assembled relation by deformationof said deformable skirt with the connection of said deformable skirtand said nozzle bcing the sole fastening for holding the assemblypermanently together.

3. In a fuel injection nozzle assembly for internal combustion engines[device of the character described], a nozzle body having an axial ductfor incoming fuel, a coaxial valve seat at the downstream extremity ofsaid duct, a coaxial counterbore downstream of said valve seat, acoaxial spring chamber downstream of said counterbore, a coaxial nozzleseat downstream of said spring chamber and a coaxial deformable skirtdownstream of said nozzle seat, a valve adapted to reciprocate in saidcounterbore, said valve having a face adapted to engage said valve seatin fluid sealing contact, said valve being provided with a pistondownstream of said face, said piston beng a reciprocable fluid sealingfit in said counterbore when said face is in Contact with said valveseat, said piston being subjcct to cylinder gas pressure in the closingdirection when the injection pressure drops in said fuel duct, saidvalve being provided with a spring seat downstream of said piston, saidnozzle having a valve lift stop and having a perforated tip at itsdownstream extremity and a flange having a substantially fiat upstreamface, and a spring engaging said spring seat of said valve and saidflange of said nozzle, whereby said spring will assist cylinder gaspressure in urging said valve face toward said valve seat, and wherebylhe cflectivc volume of said spring chamber is increased and fuel iswithdrawn which tends to eliminate fuel dribble after injection and saidnozzle engaging said deformable skirt whereby the assembly is retainedin permanent assembled relation by deformation of said dcformable skirtwith the connection of said deformable skirt and said nozzle being thesole fastening for holding the assembly permanently together.

4. In a device of the character described, a nozzle body having an axialduct for incoming fuel, a coaxial valve seat at the downstream extremityof said duct, a coaxial counterbore downstream of said valve seat, acoaxial spring chamber downstream of said counterbore, a coaxial nozzleseat downstream of said spring chamber and a coaxial deformable skirtdownstream of said nozzle seat, a valve adapted to reciprocate in saidcounterbore, said valve having a face adapted to engage said valve seatin fluid sealing contact, said valve being provided with a pistondownstream of said face, said piston being a reciprocable fluid sealingfit in said counterbore when said face is in contact with said valveseat, said valve being provided with a spring seat downstream of saidpiston, said nozzle having a hollow upstream extension forming a valvelift stop and having a perforated tip at its downstream extremity and aflange having a substantially flat upstream face and a substantiallyspherical downstream surface, and a spring engaging said spring seat ofsaid valve and said flat face of said flange of said nozzle.

5. In a device of the character described, a nozzle body having an axialduct for incoming fuel, a coaxial valve seat of greater diameter thansaid duct at the downstream extremity of said duct, a coaxialcounterbore of greater diameter than said duct downstream of said valveseat, a coaxial spring chamber of greater diameter than said counterboredownstream of said counterbore, a coaxial nozzle seat of greaterdiameter than said spring chamber downstream of said spring chamber anda coaxial deformable skirt downstream of said nozzle seat, a valveadapted to reciprocate in said counterbore, said valve having a faceadapted to engage said valve seat in fluid sealing contact, said facebeing of smaller diameter than said counterbore, said valve beingprovided with a piston downstream of said face, said piston being areciprocable fluid sealing fit in said counterbore when said face is incontact with said valve seat, said valve being provided with a springseat downstream of said piston and of smaller diameter than said springchamber, said nozzle having a hollow upstream extension forming a valvelift stop and having a perforated tip at its downstream extremity and aflange having a substantially flat upstream face and a substantiallyspherical downstream surface, and a spring engaging said spring seat ofsaid valve and said flat face of said flange of said nozzle.

[6. In a device of the character described, a nozzle body having a ductfor incoming fuel, a valve seat at the downstream extremity of saidduct, a counterbore downstream of said valve seat, a spring chamberdownstream of said counterbore, a nozzle seat downstream of said springchamber, a valve adapted to reciprocate in said counterbore, said valvehaving a face adapted to engage said valve seat in fluid sealingcontact, said valve being provided with a piston downstream of saidface, said piston being a reciprocable fluid sealing fit in saidcounterbore when said face is in contact with said valve seat, saidvalve being provided with a spring seat downstream of said piston, saidnozzle having a perforated tip at its downstream extremity and a flange,and a spring engaging said spring seat of said valve and said flange ofsaid nozzle, and means for holding said flange against said nozzle seat][7. In a device of the character described, a nozzle body having anaxial duct for incoming fuel, a coaxial valve seat at the downstreamextremity of said duct, a coaxial counterbore downstream of said valveseat, a coaxial spring chamber downstream of said counterbore, a coaxialnozzle seat downstream of said spring chamber, a valve adapted toreciprocate in said counterbore, said valve having a face adapted toengage said valve seat in fluid sealing contact, said valve beingprovided with a piston downstream of said face, said piston being areciprocable fluid sealing fit in said counterbore when said face is incontact with said valve seat, said valve being provided with a springseat downstream of said piston, said nozzle having a perforated tip atits downstream extremity and a flange, and a spring engaging said springseat of said valve and said flange of said nozzle, and means for holdingsaid flange against said nozzle seat] [8. In a device of the characterdescribed, a nozzle body having an axial duct for incoming fuel, acoaxial valve seat at the downstream extremity of said duct, a coaxialcounterbore downstream of said valve seat, a coaxial spring chamberdownstream of said counterbore, a coaxial nozzle seat downstream of saidspring chamber, a valve adapted to reciprocate in said counterbore, saidvalve having a face adapted to engage said valve seat in fluid sealingcontact, said valve being provided with a piston downstream of saidface, said piston being a reciprocable fluid sealing fit in saidcounterbore when said face is in contact with said valve seat, saidvalve being provided with a spring seat downstream of said piston, saidnozzle having a perforated tip at its downstream extremity and a flangehaving a substantially flat upstream face, and a spring engaging saidspring seat of said valve and said flange of said nozzle, and means forholding said flange against said nozzle seat] [9. In a device of thecharacter described, a nozzle body having an axial duct for incomingfuel, a coaxial valve seat at the downstream extremity of said duct, acoaxial counterbore downstream of said valve seat, a coaxial springchamber downstream of said counterbore, a coaxial nozzle seat downstreamof said spring chamber, a valve adapted to reciprocate in saidcounterbore, said valve having a face adapted to engage said valve seatin fluid sealing contact, said valve being provided with a pistondownstream of said face, said piston being a reciprocable fluid sealingfit in said counterbore when said face is in contact with said valveseat, said valve being provided with a spring seat downstream of saidpiston, said nozzle having a perforated tip at its downstream extremityand a flange having a substantially flat upstream face and asubstantially spherical downstream surface, and a spring engaging saidspring seat of said valve and said flat face of said flange of saidnozzle, and means for holding said flange against said nozzle seat] [10.In a device of the character described, a nozzle body having an axialduct for incoming fuel, a coaxial valve seat of greater diameter thansaid duct at the downstream extremity of said duct, a coaxialcounterbore of greater diameterv than said duct downstream of said valveseat, a coaxial spring chamber of greater diameter than said counterboredownstream of said counterbore, a coaxial nozzle seat of greaterdiameter than said spring chamber downstream of said spring chamber, avalve adapted to reciprocate in said counterbore, said valve having aface adapted to engage said valve seat in fluid sealing contact, saidface being of smaller diameter than said counterbore, said valve beingprovided with a piston downstream of said face, said piston being areciprocable fluid sealing fit in said counterbore when said face is incontact with said valve seat, said valve being provided with a springseat downstream of said piston and of smaller diameter than said springchamber, said nozzle having a perforated tip at its downstream extremityand a flange having a substantially flat upstream face and asubstantially spherical downstream surface, and a spring engaging saidspring seat of said valve and said flat face of said flange of saidnozzle, and means for holding said flange against said nozzle seat] I].In a device of the character described, a nozzle body having an axialduct for incoming fuel, a coaxial valve seat at the downstream extremityof said duct, a coaxial counterbore downstream of said valve seat, acoaxial spring chamber downstream of said counterbore, a coaxial nozzlescat downstream of said spring chamber and a coaxial deformable skirtdownstream of said nozzle seat, a valve adapted to reciprocate in saidcounterbore, said valve having a face adapted to engage said valve scatin fluid scaling contact, said valve being provided with a pistondownstream of said face, said piston being a reciprocablc fluidthrottling fit in said counterbore when said face is in contact withsaid valve seat, said valve being provided with a spring seat downstreamof said piston, said nozzle having a hollow upstream extension forming avalve lift stop and having a perforated tip at its downstream extremityand a flange having a substantially flat upstream face and asubstantially spherical downstream surface, and a spring engaging saidspring seat 0) said valve and said flat face of said flange of saidnozzle.

12. In a device of the character described, a nozzle body having anaxial duct for incoming fuel, a coaxial valve seat of greater diameterthan said duct at the downstream extremity of said duct, a coaxialcounterbore of greater diameter than said duct downstream of said valveseat, a coaxial spring chamber of greater diameter than said counterborcdownstream of said counterborc, a coaxial nozzle seat of greaterdiameter than said spring chamber dmvnstream of said spring chamher anda coaxial deformable skirt downstream of said nozzle seat, a valveadapted to reciprocate in said counterbore, said valve having a faceadapted to engage said valve seat in fluid sealing contact, said facebeing of smaller diameter than said counter-bore, said valve beingprovided with a piston downstream of said face, said piston being areciprocable fluid throttling fit in said counterbore when said face isin contact with said valve seat, said valve being provided with a springseat downstream of said piston and of smaller diameter than said springchamber, said nozzle having a hollow upstream extension forming a valvelift stop and having a perforated tip at its downstream extremity and aflange having a substantially flat upstream face and a substantiallyspherical downstream surface, and a spring engaging said spring seat ofsaid valve and said flat face of said flange of said nozzle.

13. In a relatively simple, compact and economical fuel injection nozzleassembly for internal combustion engines which requires no fuelleak-ofl, a nozzle body having fuel duct means for incoming fuel, saidfuel duct means having a valve seat at the downstream e.\'tremity ofsaid fuel duct, fuel passage means in said nozzle body dmvnstteam of andcommnnicating with said duct means, said fuel passage means having acounterlrore downstream of said valve scat and a spring chamberdownstream of said counterbore, said nozzle body having deformable skirtmeans downstream of said nozzle seat, a nozzle downstream of said springchamber, valve means mounted in said counterbore for reciprocationtherein, said valve means having a face adapted to engage said valveseat of said fuel duet means in fluid sealing contact, said valve meanshaving retraction piston means and a spring seat downstream of saidface, said retraction piston means being in said counterbore when saidvalve face of said valve means is in engagentent with said valve seat ofsaid fuel duct means, said retraction piston means being subject tocylinder gas pressure in the closing direction when the injection fuelpressure drops in said fuel duct means, and spring means in said springchamber and engaging said spring seat on said valve and said nozzlewhereby said spring means will assist cylinder gas pressure in urgingsaid valve face toward said valve seat, and whereby the eflective volumeof said spring chamber is increased and fuel is withdrawn which tends toeliminate fuel dribble after injection, said nozzle engaging saiddeformable skirt means whereby said assembly is retained in permanentassembled relation by deformation of said deformable skirt means.

14. In a relatively simple, compact and economical fuel injection nozzleassembly for internal combustion engines which requires no fuelleak-off, a nozzle body having fuel duct means for incoming fuel, saidfuel duct means having a valve seat at the downstream extremity of saidduct means, a fuel passage in said nozzle body communicating with saidduct means, said fuel passage having a counterbore downstream of saidvalve seat and a spring chamber downstream of said counterbore, saidnozzle body having a nozzle seat downstream of said spring chamber anddeformable skirt means downstream of said nozzle seat, valve meansmounted in said counter-bore for reciprocation therein, said valve meanshaving a face adapted to engage said valve seat in fluid sealingcontact, said valve means having retraction piston means and a springseat downstream of said face, said retraction piston means being in saidcounterbore when said valve face is in engagement with said valve seat,said retraction piston means being subject to cylinder gas pressure inthe closing direction when said valve face is in engagement with saidvalve seat, and nozzle means engaging said deformable skirt meanswhereby said assembly is retained in permanent assembled relation bydeformation of said deformable skirt means, and spring means engagingsaid spring seat on said valve and said nozzle whereby said spring meanswill assist cylinder gas pressure in urging said valve face toward saidvalve seat, and whereby the cfiective volume of said spring chamber isincreased and fuel is withdrawn which tends to eliminate fuel dribbleafter injection.

I5. In a relatively simple, compact and economical fuel injection nozzleassembly for internal combustion engines which requires no fuelltak-o,lf, a nozzle body having fuel duct means for incoming fuel, saidfuel duct means having a valve seat at the downstream extremity of saidfuel duct means, fuel passage means in said nozzle body downstream ofand communicating with said duct means, said fuel passage means having acounter-bore downstream of said valve seat and a spring chamberdownstream of said counterbore, said nozzle body having deformable skirtmeans downstream of said spring chamber, a nozzle downstream of saidspring chamber and supported by deformation of said deformable skirtmeans of said nozzle body, valve means mounted in said counterbore forreciprocation therein, said valve means having a face adapted to engagesaid valve seat of said fuel duct means in fluid sealing contact, saidvalve means having retraction piston means and a spring scat downstreamof said face, said retraction piston means being in said counterborewhen said valve face of said valve means is in engagement with saidvalve seat of said fuel duct means, said retraction piston means beingsubject to cylinder gas pressure in the closing direction. when theinjection fuel pressure drops in said fuel duct means and spring meansin said spring chamber and engaging said spring seat on said valve andsaid nozzle whereby said spring means will assist cylinder gas pressurein urging said valve face toward said valve seat, and whereby theefiective volume of said spring chamber is incerased and fuel iswithdrawn which tends to eliminate fuel dribble after injection, saidnozzle being secured to said nozzle body engaging said deformable shirtmeans whereby said assembly is retained in permanent assertibledrelation by deformation of said deformable skirt means, said nozzlehaving a valve lift stop for limiting the movement of said valve means.

I6. In a relatively simple, compact and economical fuel injection nozzleassembly for internal combustion engines which requires no fuelleak-off, a nozzle body having fuel duct means for incoming fuel, saidfuel duct means having a valve seat at the downstream extremity of saidduct means, a fuel passage in said nozzle body communicating with saidduct means, said fuel passage having a counterbore downstream of saidvalve seat and a spring chamber downstream of said counterbore, saidnozzle body having a nozzle seat downstream of said spring chamber anddeformable skirt means downstream of said nozzle seat, valve meansmounted in said counter-bore for reciprocation therein, said valve meanshaving a face adapted to engage said valve seat in fluid sealingcontact, said valve means having retraction piston means and a springseat downstream of said face, said retraction piston means being in saidcounterbore when said valve face is in engagement with said valve seat,said retraction piston means being subfeet to cylinder gas pressure inthe closing direction when said valve face is in engagement with saidvalve seat, and nozzle means engaging said deformable skirt meanswhereby said assembly is retained in permanent assembled relation bydeformation of said deformable skirt means, and spring means engagingsaid spring seat on said valve and said nozzle whereby said spring meanswill assist cylinder gas pressure in urging said valve face toward saidvalve seat, and whereby the effective volume of said spring chamber isincreased and fuel is withdrawn which tends to eliminate fuel dribbleafter injection, said nozzle having a valve lift stop for limiting themovement of said valve means.

17. In a relatively simple, compact and economical fuel injection nozzleassembly for internal combustion engines which requires no fuelleak-ofl, a nozzle body having fuel duct means for incoming fuel, saidfuel duct means having a valve seat at the downstream extremity of saidduct means, a fuel passage in said nozzle body communicating with saidduct means, said fuel passage having a counterbore downstream of saidvalve seat and a spring chamber downstream of said counterbore, saidnozzle body having a nozzle seat downstream of said spring chamber anddeformable skirt means downstream of said nozzle seat, valve meansmounted in said counterbore for reciprocation therein, said valve meanshaving a face adapted to engage said valve seat in fluid sealingcontact, said valve means having retraction piston means and a springseat downstream of said face, said retraction piston means being in saidcounter bore when said valve face is in engagement with said valve seat,said retraction piston means being subject to cylinder gas pressure inthe closing direction when said valve face is in engagement with saidvalve seat, and nozzle means engaging said deformable skirt meanswhereby said assembly is retained in permanent assembled relation bydeformation of said deformable skirt means, and spring means engagingsaid spring seat on said valve and said nozzle whereby said spring meanswill assist cylinder gas pressure in urging said valve face toward saidvalve seat, and whereby the effective volume of said spring chamber isincreased and fuel is withdrawn which tends to eliminate fuel dribbleafter injection, said spring seat being downstream of said retractionpiston.

18. In a relatively simple, compact and economical fuel injection nozzleassembly for internal combustion engines which requires no fuelleak-ofi, a nozzle body having fuel duct means for incoming fuel, saidduct means having a valve seat at the downstream extremity of said ductmeans, a fuel passage in said nozzle body communicating with said ductmeans, said fuel passage having a counter- 1O bore downstream of saidvalve seat and a spring chamber downstream of said counterbore, saidnozzle body having a nozzle seat downstream of said spring chamber anddeformable skirt means downstream of said nozzle seat, valve meansmounted in said connterbore for reciprocation therein, said valve meanshaving a face adapted to engage said valve seat in fluid sealingcontact, said valve means having retraction piston means and a springseat downstream of said face, said retraction piston means being in saidcounterbore when said valve face is in engagement with said valve seat,said retraction piston means being subject to cylinder gas pressure inthe closing direction when said valve face is in engagement with saidvalve seat, and nozzle means engaging said deformable skirt meanswhereby said assembly is retained in permanent assembled relation bydeformation of said deformable skirt means, and spring means engagingsaid spring seat on said valve and said nozzle whereby said spring meanswill assist cylinder gas pressure in urging said valve face toward saidvalve seat, and whereby the eficctive volume of said spring chamber isincreased and fuel is withdrawn which tends to eliminate fuel dribbleafter injection, said n zzle having a perforated tip at its downstreamextremity.

References Cited by the Examiner The following references, cited by theExaminer, are of record in the patented file of this patent or theoriginal patent.

UNITED STATES PATENTS 2,387,690 10/1945 Ste1ze1 239-533 2,623,78212/1952 Gustafson 239533 2,623,783 12/1952 Gustafson 239533 2,665,1671/1954 High 239533 FOREIGN PATENTS 902,982 1/ 1 945 France.

835,660 4/ 1952 Germany.

348,712 5/1931 Great Britain.

EVERETT W. KIRBY, Primary Examiner.

